emails: add djmail proxy model, cleanup_email cmd

- new email message model
    - proxy djmail messages and add model manager with helper methods
- cleanup_email cmd deletes draft emails with subject and optionally
  clears user flag
    - requires email subject
    - optional argument for userprofile flag field to clear sent status

Bug: T409420
Bug: T412427

Author: jsnshrmn

TWLight/emails/backends/mediawiki.py

@@ -255,7 +255,6 @@ def _send(self, email_message):
                 if not emailable:
                     logger.warning("User not emailable, email skipped.")
                     continue
-
                 # POST request to send an email
                 email_params = {
                     "action": "emailuser",

TWLight/emails/management/commands/__init__.py

@@ -0,0 +1,29 @@
+# -*- coding: utf-8 -*-
+from django.core.management.base import BaseCommand
+
+from TWLight.emails.models import Message
+
+
+class Command(BaseCommand):
+    help = "Delete draft emails."
+
+    def add_arguments(self, parser):
+        parser.add_argument(
+            "--subject",
+            type=str,
+            required=True,
+            help="Email subject",
+        )
+        parser.add_argument(
+            "--userprofile_flag_field",
+            type=str,
+            help="Optionally unset userprofile boolean that tracks sent status for messages with the specified subject",
+        )
+
+    def handle(self, *args, **options):
+        subject = options["subject"]
+        userprofile_flag_field = options["userprofile_flag_field"]
+
+        Message.objects.bulk_cleanup_drafts(
+            subject=subject, userprofile_flag_field=userprofile_flag_field
+        )

TWLight/emails/management/commands/cleanup_email.py

@@ -0,0 +1,51 @@
+# -*- coding: utf-8 -*-
+from django.contrib.auth.models import User
+from django.db import models
+
+from djmail.models import Message as DjMail
+
+from TWLight.users.models import UserProfile
+
+
+class MessageManager(models.Manager):
+    def drafts(self, subject=None):
+        if subject is not None:
+            return self.filter(status=DjMail.STATUS_DRAFT, subject=subject)
+        return self.filter(status=DjMail.STATUS_DRAFT)
+
+    def users_with_drafts(self, subject=None):
+        email_addresses = self.drafts(subject).values_list("to_email", flat=True)
+
+        return User.objects.select_related("userprofile").filter(
+            email__in=email_addresses
+        )
+
+    def userprofiles_with_drafts(self, subject=None):
+        email_addresses = self.drafts(subject).values_list("to_email", flat=True)
+
+        return UserProfile.objects.select_related("user").filter(
+            user__email__in=email_addresses
+        )
+
+    def bulk_cleanup_drafts(self, subject=None, userprofile_flag_field=None):
+        if subject is not None and userprofile_flag_field is not None:
+            userprofiles = self.userprofiles_with_drafts(subject=subject).filter(
+                **{userprofile_flag_field: True}
+            )
+            for userprofile in userprofiles:
+                setattr(userprofile, userprofile_flag_field, False)
+            UserProfile.objects.bulk_update(
+                userprofiles, [userprofile_flag_field], batch_size=1000
+            )
+
+        if subject is not None:
+            self.drafts(subject=subject).delete()
+
+
+class Message(DjMail):
+    class Meta:
+        proxy = True
+        ordering = ["uuid"]
+        app_label = "emails"
+
+    objects = MessageManager()

TWLight/emails/models.py

@@ -23,7 +23,6 @@
 """
 
 from djmail import template_mail
-from djmail.models import Message
 from djmail.template_mail import MagicMailBuilder, InlineCSSTemplateMail
 import logging
 import os